The cable that came with my Moto G improves on this by making the top, logo side slightly concave and the other side slightly convex. You can literally feel which way up you've got the plug.
And I still preferentially use my Palm Pre cables (back in the day, I dremmeled down the plastic housing of another usb-micro I had so it would fit in the touchstone, since I never unplugged that one, and could use the palm-pre one for other uses).
That only helps when you know the cable beforehand. The cable that came with my Motorola RAZR i cable has the high relief on one side of the connector, while the one from my Nexus 7 has it on the other side.
1. The cable has a logo.
2. You can see the logo.
3. The device and cable both conform to the standard.
4. The port is not vertical.
5. The device you are plugging in is not on it's side or upside down.
6. The user is sober and of a clear, calm mind.